1. Field of the Invention
The invention relates to a retractor for holding an aperture open, and particularly an eyelid speculum.
2. Discussion of the Prior Art
A device referred to as an “eye speculum” or a “retractor” is frequently used for various medical procedures on the eye, to hold the upper and lower eyelids apart, in order to have access to the eye. Conventional eye specula include rigid, hinged metal devices, some withs an anti-close locking wheel to fix the speculum to a desired open position, as well as wire devices that have a live hinge, without any means for fixing the speculum to a particular open position.
Understandably, the hinged metal devices with the anti-close locking wheel are expensive to manufacture. They have multiple parts that require assembly, some of the parts require precision machining, etc. On the other hand, the wire devices with the live hinge can be difficult to use for a number of reasons. It is possible, for example, that when the two arms of the device are squeezed to bring the blades together for insertion under the eyelids, that the two arms become misaligned and, consequently, that a torque is exerted on the arms, causing the device to spring out from the operator's hand. The problem of a torque on the device also arises, when the pressures exerted on the respective blades by the upper and lower eyelids is very different.
Some conventional devices are not symmetrically constructed and, thus, a separate device must be used for the left eye and for the right eye. Some conventional devices have a solid upper blade, a shelf-like construction, for holding the eyelid open. Wire devices with a live hinge often have open wire blades with only two contact points retracting each lid. These constructions can create pressure points along the eyelid that cause discomfort to the patient, or damage the eyelid tissue and increase the risk of ptosis, commonly referred to as “droopy eyelid.”
What is needed, therefore, is an eye speculum device that is inexpensive to manufacture and that is simple to use. What is further needed is such a device that applies a minimum amount of pressure to the patient's eye or eyelids, yet reliably holds the eyelid open. What is yet further needed is such a device that reduces the risk of pressure points along the patient's eyelid.